Multi-lead hermetic power package with high packing density

Abstract

An hermetic package for power semiconductor devices is disclosed. The package includes a generally rectangular cavity with leads extending through the walls thereof. The bottom of the cavity is defined by a base which includes a pair of mounting tabs protruding from opposite corners thereof. The mounting tabs are configured to allow the packages to be nested together. A cover attached to the walls provides a hermetically sealed package.

I claim: 
     
       1. A package for a semiconductor device comprising: a semiconductor device mounting cavity of generally rectangular configuration, the cavity being defined by walls surrounding its periphery;   a base affixed to the semiconductor device mounting cavity, the base having a spaced-apart pair of mounting tabs extending from diagonally opposite corners of the walls of the cavity, the mounting tabs being adapted to enable the base to be affixed to a mounting surface, wherein the mounting tabs each extend outward from the base by an equal distance and occupy an area equal to about one-half of the area defined by the length of the base times the width of the tab; and   at least two leads extending through openings in the walls of the cavity to enable electrical signals to communicate from within the cavity to outside the walls.   
     
     
       2. A package as in claim 1 wherein: each of the first and second tabs are tapered to become smaller further from the base.   
     
     
       3. A package as in claim 2 wherein: the first and second tabs have geometries that are inverted mirror images of each other.   
     
     
       4. A package as in claim 3 wherein: the first tab includes a mounting hole; and   the second tab includes a mounting slot.   
     
     
       5. A package as in claim 1 wherein the at least two leads comprise: two leads extending through openings in one wall of the cavity; and   a plurality of leads extending through an opposite wall of the cavity.   
     
     
       6. A package as in claim 5 wherein the two leads enable coupling the package to be source of electrical power. 
     
     
       7. A package as in claim 6 wherein the plurality of leads comprises five leads. 
     
     
       8. A package as in claim 1 wherein the cavity is defined by four walls extending upward from the base to thereby define the rectangular configuration. 
     
     
       9. A package as in claim 8 wherein: the openings in the walls for the leads are larger than the leads to define an annular region about each lead where it passes through the wall; and   an electrically insulating material is disposed in the openings to electrically isolate the leads from the walls.   
     
     
       10. A package as in claim 1 further comprising: a cover disposed over the cavity and affixed to the walls to enclose the cavity.   
     
     
       11. A package as in claim 10 wherein the cover hermetically encloses the cavity.